Hayward Bulkhead O-Ring for SwimClear Cartridge Filters, DEX360M

The Hayward DEX360M is the bulkhead o-ring for SwimClear cartridge filters. It is the genuine Hayward OEM part.

Which filters

SwimClear cartridge filters C2020, C2025, C3020, C3025, C4020, C4025, C5020, C5025 and C5520, and the Super Star Clear cartridge filters C-2000, C-3000, C-4000, C-4500, C-5000 and C-5500.

What it does

An o-ring is a simple round seal squeezed between two parts. This one seals the bulkhead connection on the tank. It works by springing back against both surfaces, and that is exactly what it loses with age: the rubber hardens, takes a permanent set in the groove, and the connection starts to weep.

Fitting it

Clean the groove out before the new ring goes in, and use a pool rated o-ring lubricant. That lets the ring seat evenly instead of pinching or rolling as the joint comes together, which is the other common reason a fresh o-ring still leaks.